Process of treating clay and like materials.



UNITED STATES PATENT OFFICE. FIR'MAN THOMPSON, OF NEWARK, DELAWARE, ASS IGNOR TO THE CRESCENT CIJAY REFINING COMPANY, OF BALTIMORE, MARYLAND, A CORPORATION OF MARYLAND.

PROCESS OF TREATING- CLAY AND LIKE MATERIALS.

No Drawing.

To all whom it may concern Be it known that I, FIRMAN THOMPSON, a

citizen of the United States, residing at Newark, in the county of Newcastle and uses referred to.

Ferruginous clay and llke materlals are discolored by iron in the form of iron oxid.

This iron may be removed by the action of strong acids, but such treatment, aside from the dlsadvantage of being prohibitively expensive, injuriously modifies the character of the clay, releasing a part or all of the combined Water, and rendering the material to a greater or less extent, unfit for uses in connection with which it is most valuable.

For many years attempts have been made by those skilled in the art to bleach ferruginous clay and the like Without altering the character or composition thereof either by removing valuable constituents therefrom, setting free the combined water, increasing the proportion of the silica content or otherwise chemically decomposing or detrimen tally aflecting such material, but it has K hitherto been impossible to effect such bleaching action without destroying or materially. lessening the value of such materials for theuses above enumerated.

New I have descovered that it is possible to purify ferruginous clays and like materials by the elimination of practically all of the iron therefrom without injuriously affecting the character of the material under treatment even as regards the combined water therein, by subjecting the same to the action of'nascent hydrochloric acid, the gas being developed in contact with theclay or like materials under treatment and suflicient and washing out the resulting water to produce a dilute solution of the gas iron compound or compounds with water.

I have also discovered that some clays and other similar materials may be practically Specification of Letters Patent.

Patented Mar. '16,

Application filed August 2a, 1913. Serial No. 786,290.

wholly freed from iron by subjecting the same to the action of a dilute solution of hydrochloric acid under heat and pressure, and washing out the resulting iron compound, without injury to the clay illustration its application to clay, the clay is first mixed with weak brine, 100 pounds of claybeing treated with brine produced by d ssolvmg four pounds'of sodium chlorid in 100 pounds-of water. Seven pounds of sulfuric acid of B. are then added andthe mixture agitated by stirring or otherwise 'unt1l a homogeneous paste results.

v begmade in a digester or' other chamber adapted to be hermetically The mixture may sealed, or the materials maybe brought to-, gether and the resulting paste run into the digester or like chamber. After being placed in the digester and sealed therein the mixture is subjected to the action of steam under a thesquare inch for-from 10 minutes to an hour, depending upon the characterof the clay under treatment, the steam being preferably passed through the mixturethereby agitating it and hastening-the reaction.

The treatment with steam is ordinarily continued until a test sample'of the clay removed and washed with water shows the practically complete absence of iron. After treatment with the steam has been com leted the clay is .washed with water, prefera ly in a filter press, andthe clay, after being dried, is then ready for use.

In the treatment of clay containing approximately 1 per cent. of oxid or oxids of iron, by the process described, it is possible to effect the practically complete elimination the composition of the clay; even the content of combined water not being appreciably afl'ected bv 'the treatment;

It will be understood that different materials will requiredifl'erent strengths of reagents and different-times of treatment with the steam under pressure and that forsome' uses the iron need be only partially removed, in' which case the expense of the process or rially lessened.

It is also to be understood that while I prefer to employ nascent hydrochloric acid as described, practical success may in some cases be obtained by the use of hydrochloric or the like. In the practice of my process in its pre-. ferred' form, consldering for the purpose of pressure of preferably 80 pounds toof iron in 17 minutes and without-changing the time of operation or both will be mateacid in dilute solution. Where hydrochloric acid in solution is used I preferably employ the gas in the same strengthpf solution which is produced in the practice of my process as hereinbefore set forth.

. It is further to be understood that various changes may be made in the details of pro cedure, time of operation and strength of reagents employed and that equivalents of the reagents may be resorted to, all without departure from the spirit of my invention or the scope of the subjoined claims.

Having described my invention, I claim:

-1. The process of treating clay and like materials to remove iron therefrom without decreasing the plasticity of the clay or the like, which consists in subjecting the same to the action of dilute hydrochloric acid under heat and pressure and removing the resulting iron compoundor compounds produced.

2. The process of treating clay and like materials to remove iron therefrom withoutdetrimental action on such materials, which consists in subjecting the same to the action of dilute hydrochloric acid and steam under pressure and removing the resulting iron compound or compounds produced.

3. The process of treating clay and like materials to remove iron therefrom without decreasing the plasticity of the clay or the like, which consists in developing nascent detrinriental action upon such -materials,'

which consists in developing nascent hydro- A chlorio acid in contact therewith and sufficient water to produce-a dilute solution of the acid, subjecting the material under treatment to the action of the solution. and

steam under pressure and removing the resulting 'iron compound or compounds pro .duced.

5. The process of treating clay and like materials to remove iron therefrom without decreasing the plasticity of the clay or the like, which consists in treating the same-i: withan alkali 'metal chlorid, an acid and suflicient water to produce a dilute solution I of acid and chlorid, subjecting the mixture to heatand-nressure and removing theiron compound orcompounds produced.v

6. The process-of treating clay and like materials-to'remove iron therefrom without injury to the clay'or the like ywhich consists in treating the same with 5M} alkali metal chlorid, an acid andsufiicient water to produce a dilute solution of acid and chlorid, subjecting the mixture to the action of steam under pressure and removing the iron compound or compounds produced.

7. The process of treating clay and like materials to remove iron therefrom without decreasing the plasticity of the clay or the like, which consists in treating the same with sodium chlorid, sulfuric acid and sufficient water to produce a dilute solution ofacid and-chlorid, subjecting the mixture to the action of heat and pressure and removing the iron compound or compounds produced.

' 8. The process of treating clay and like materials to remove iron therefrom without injury to the clay or the like, which consists in treating the same with sodium chlorid, sulfuric acid and sufficient water to produce a dilute solution of acid and chlorid, subjecting the mixture to the action of steam under pressure and removing the iron compound or compounds produced.

9. The process of treating clay and like materials to remove iron therefrom without like, comprising treating the same with sodium chlorid and sulfuric acid in approximately the proportions of 7 parts by weight of the acid of 60- B. and 4: parts by weight of sodium chloridand water, subjecting the mixture to the action of heat and pressure and removing the iron compound or compounds produced. a

10. The process of treating clay and like materials to remove iron therefrom without injury to the clay or' the like, comprising treating the same with sodium chlorid and sulfuric acid in approximately the proportions of 7 parts by weight of the acid of. 60

' B. and 4: parts by weight of sodium chlorid and water, subjecting the mixture to the action of steam under pressure and removing the iron compound or com ounds produced.

11. The process of treating clay, and like materials to remove iron therefrom without injury to the clay or the like, comprising H. H. Mons/an, Jr.

treating the same with sodiumchlorid and sulfuric acid in dilute solution in approxi- 

